$ sed -n "/00:00:01/p" nls.log 
     1  223.104.7.59 - - [05/Dec/2018:00:00:01 +0000] "
     4  139.180.131.123 - - [05/Dec/2018:00:00:01 +0000] "
     9  139.180.131.123 - - [05/Dec/2018:00:00:01 +0000] "
    10  117.136.39.87 - - [05/Dec/2018:00:00:01 +0000] "
$ sed -n "/00:00:02/p" nls.log 
     2  123.125.71.60 - - [05/Dec/2018:00:00:02 +0000] "
     3  141.8.142.131 - - [05/Dec/2018:00:00:02 +0000] "
$ sed -n "/00:00:01/,/00:00:02/p" nls.log 
     1  223.104.7.59 - - [05/Dec/2018:00:00:01 +0000] "
     2  123.125.71.60 - - [05/Dec/2018:00:00:02 +0000] "
     4  139.180.131.123 - - [05/Dec/2018:00:00:01 +0000] "
     5  40.77.167.60 - - [05/Dec/2018:00:00:03 +0000] "
     6  204.141.42.226 - - [05/Dec/2018:00:00:04 +0000] "
     7  40.77.167.60 - - [05/Dec/2018:00:00:04 +0000] "
     8  127.0.0.1 - - [05/Dec/2018:00:00:04 +0000] "
     9  139.180.131.123 - - [05/Dec/2018:00:00:01 +0000] "
    10  117.136.39.87 - - [05/Dec/2018:00:00:01 +0000] "
    11  121.15.166.147 - - [05/Dec/2018:00:00:07 +0000] "
    12  219.142.131.122 - - [05/Dec/2018:00:00:07 +0000] "
    13  61.132.54.2 - - [05/Dec/2018:00:00:07 +0000] "
    14  103.75.152.102 - - [05/Dec/2018:00:00:07 +0000] "
    15  222.66.96.129 - - [05/Dec/2018:00:00:07 +0000] "
    16  180.168.166.28 - - [05/Dec/2018:00:00:07 +0000] "
    17  114.94.126.62 - - [05/Dec/2018:00:00:07 +0000] "
    18  61.135.169.90 - - [05/Dec/2018:00:00:07 +0000] "
    19  120.36.255.107 - - [05/Dec/2018:00:00:07 +0000] "
    20  14.21.33.152 - - [05/Dec/2018:00:00:07 +0000] "

sed -n '/s1/,/s2/p' file
sed 会逐行读取文件到模式空间，也就是一个临时缓存，然后执行 sed 后面的命令，然后输出打印模式空间的内容，然后清空模式空间；
接着读文件的下一行，重复前面的步骤，直到文件内容处理完为止。
如果没有-n，匹配到的内容比如 s1 会被再次打印，s1 总共就会被打印 2 次 (假设 s1 只匹配到 1 行)。
如果有-n 那么会抑制默认打印，只打印匹配到的内容。
'/s1/,/s2/p' 表示打印 s1 和 s2 所在行及之间的内容。
所以，可以推断出 s1 和 s2 直接的内容是被存到模式空间，并且会被打印的。
那么，当 s1 匹配成功，s2 匹配失败时，打印的是 s1 及 s1 到最后 1 行。
案例中，$ sed -n "/00:00:01/,/00:00:02/p" nls.log 的/00:00:01/的所在 4/9/10 行都必/00:00:02/所在 2/3 行大，
而/00:00:01/所在行是 1，所以会打印所有。